<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
  </head>
  <style>
    .bigbox {
      width: 800px;
      height: 800px;
      background: green;
      margin-top: 100px;
      margin-left: 100px;
    }
  </style>
  <body>
    <div class="bigbox">
      <div class="box1"></div>
      <div class="box2"></div>
      <div class="box3"></div>
      <div class="box4"></div>
    </div>
  </body>
</html>
